COMPARISON OF DIFFERENT BLADDER AUTOAUGMENTATION TECHNIQUES IN A RABBIT MODEL

Objective To compare the urodynamic, radiological and histopathologica l findings of a bladder autoaugmentation method combined with differen t seromuscular enterocystoplasty (mucosectomized) techniques and the r ectus abdominis muscle-flap (RAMF) technique, and thus devise a method that may eliminate the potential risks of bladder autoaugmentation. M aterials and methods The study comprised 20 male New Zealand White rab bits in four groups. In group 1 (control), an autoaugmentation model w as created by incising the detrusor muscle of the bladder, forming a l arge wide-mouthed bladder diverticulum. In group 2, a full-thickness R AMF with an intact vascular supply was used to cover the augmented bla dder wall. In groups 3 and 4, besides the autoaugmentation procedure, a 5 cm ileal segment with an intact vascular supply was prepared and t he mucosal layer of the segment removed, In group 3, the mucosectomize d surface of the ileal graft was used to cover the autoaugmented bladd er (seromuscular ileocystoplasty, SMEC) and in group 4, the serosal su rface of the pedunculated ileal graft was used in reverse to cover the autoaugmented bladder wall (reversed SMEC, RSMEC). All groups were fo llowed using intravenous pyelography (IVP), voiding cysto-urethrograph y (VCUG), urodynamic investigations and histopathological analysis for 2 months post-operatively. Results In all groups except 2 (RAMF), a d iffuse bulging of the bladder wall was detected on IVP and VCUG. In gr oups 1, 3 and 4, there was a significant increase in mean bladder capa city and the compliance also increased. However, in group 2 there was a significant reduction in bladder capacity and compliance. and the hi stopathological analysis showed severe fibrosis. The fibrotic changes were moderate in groups 1 and 4 and mild in group 3, Conclusions The u rodynamic studies, IVP, VCUG and histopathology suggested that the SME C technique decreased the potential risks of bladder autoaugmentation, had minimal side-effects and was the most appropriate coat over the u roepithelium after bladder autoaugmentation.